The long-term aim of this project is to define the effects of drugs of abuse on brain structure and metabolite concentrations, as well as the behavioral correlates of those effects, in infants and children who have been exposed to those drugs during fetal development. We will obtain high-resolution anatomical MRI, magnetic resonance spectroscopy (MRS), and Diffusion Tensor Imaging (DTI) scans in 90 newborn infants exposed to drugs of abuse during fetal development (45 exposed to opiates and 45 exposed to cocaine) and 45 matched, unexposed newborn controls. We will measure and compare regional brain volumes, metabolite levels, and white matter fiber pathways across groups of exposed and unexposed infants. We will assess the physical, neurological, motor, and cognitive development of these infants at regular intervals until the infants are 36 months old. We will then determine whether brain MRI measures at birth correlate with differential neurodevelopmental outcome across the 3 groups of newborns. This study promises to define the consequences of prenatal exposure to cocaine and opiates on brain structure and metabolite concentrations. Defining these consequences will in turn help to identify the pathophysiological mediators and suggest possible prevention and early intervention strategies.